You can simply switch to the 'editing' view to see the markup that is used to create the following basic text-formatting examples.

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!heading   = small heading with text 'heading'
!!heading  = medium heading with text 'heading'
!!!heading = large heading with text 'heading'

''text''   = prints 'text' in italic.
__text__   = prints 'text' in bold.
{{text}}   = prints 'text' in monospaced font.

* text     = makes a bulleted list item with 'text'
# text     = makes a numbered list item with 'text'

----       = Make a horizontal ruler. Extra '-' is ignored.
\\         = force a line break

[link]     = creates a hyperlink to an internal WikiPage called 'Link'.
[this is also a link] = creates a hyperlink to an internal WikiPage called
'ThisIsAlsoALink'.
[click here|link] = creates a hyperlink to an internal WikiPage called
'Link', but displays the text 'click here' to the
user instead of 'Link'.
[1]        = Makes a reference to a footnote numbered 1.
[#1]       = Marks the footnote number 1.
[link]    = creates text '[link]'.